There are conventional techniques for detecting an input of a breath blown against a microphone. For example, a conventional breath blowing determination device is provided in advance with a frequency distribution representing a sound made by breath, and detects the frequency distribution of a sound input on a microphone. Then, the determination device determines whether or not a breath-blowing input has been made by determining whether or not the provided frequency distribution matches with the frequency distribution of the detected input sound.
With conventional methods, however, the processing burden may become large due to frequency analysis and frequency distribution matching processes.
Thus, the present application discloses a storage medium storing an information processing program, an information processing device, an information processing system, and a sound determination method, with which it is possible to determine an input sound by a simple method.
(1)
An example storage medium described herein is a computer-readable storage medium storing an information processing program to be executed by a computer of an information processing device for determining a sound input to a microphone. The information processing program causes the computer to function as an obtaining unit, a mean amplitude calculation unit, and a determination unit. The obtaining unit obtains data of a sound detected by the microphone. For a sound of a predetermined determination segment, the mean amplitude calculation unit calculates a mean amplitude, which is an average amplitude, by using the obtained data of the sound, for each of a plurality of partial segments included in the determination segment. The determination unit determines whether or not the sound input to the microphone is a predetermined type of a sound based on the mean amplitudes for the partial segments.
The term “determining whether or not the sound is a predetermined type of a sound” as set forth above means to include “determining whether the sound is a predetermined type of a sound or another type of a sound”. That is, the determination unit may be a unit that only detects the predetermined type of a sound and does not detect other types of sounds, or may be a unit that detects, and distinguishes between, the predetermined type of a sound and other types of sounds.
With configuration (1) above, based on the mean amplitudes for the partial segments, it is possible to know, by a simple method, the amount of frequency components below the frequency corresponding to the length of a partial segment. That is, with configuration (1) above, it is possible to make the determination by the simple method of calculating the mean amplitudes, without having to perform a complicated process such as frequency analysis (frequency conversion) and frequency spectrum pattern matching.
(2)
The determination unit may calculate an absolute value of the mean amplitude for each partial segment, and make the determination based on the calculated absolute values.
With configuration (2) above, the determination is made based on the absolute value of the mean amplitude, which is an index representing the amount of components below the frequency corresponding to the partial segment of the sound of the determination segment. That is, the determination can be made based on the amount of components below the frequency corresponding to the length of a partial segment. Thus, it is possible to precisely make the determination.
(3)
The determination unit may calculate an average value among the absolute values, and make the determination based on a determination value which is based on the calculated average value.
With configuration (3) above, by using the average value, it is possible to easily determine a particular type of a sound (e.g., a sound made by breath blowing) having components below the frequency corresponding to the length of a partial segment.
(4)
The determination unit may calculate a difference between two mean amplitudes for two partial segments next to each other within the determination segment for each pair of two partial segments next to each other, and make the determination by using a determination value which is based on absolute values of the differences.
With configuration (4) above, it is possible to determine a particular type of a sound (e.g., a sound made by breath blowing) having components below a frequency corresponding to the length of a partial segment and above a frequency corresponding to the length of two partial segments. Then, it is possible to distinguish between a particular type of a sound and another type of a sound having a lower frequency than the sound, and it is therefore possible to more precisely make the determination.
(5)
The determination unit may calculate a difference between a mean amplitude for one partial segment and a mean amplitude for a group segment, which is made up of two or more successive partial segments including the one partial segment for each partial segment, and make the determination by using a determination value which is based on absolute values of the differences.
With configuration (5) above, it is possible to determine a particular type of a sound having components below a frequency corresponding to the length of a partial segment and above a frequency corresponding to the length of a partial segment multiplied by a predetermined number (the number of partial segments included in a group segment). Then, it is possible to distinguish between a particular type of a sound and another type of a sound having a lower frequency than the sound, and it is therefore possible to more precisely make the determination.
(6)
The determination unit may make the determination based on a comparison between the determination value and a predetermined threshold value.
With configuration (6) above, it is possible to easily perform the determination process using the determination value.
(7)
The determination unit may make the determination based on a ratio of the determination value with respect to a sound volume over the determination segment.
With configuration (7) above, it is possible to precisely perform the determination process using the determination value.
(8)
The determination unit may determine whether or not a sound input to the microphone is a sound made by breath blowing.
With configuration (8) above, it is possible to detect, by a simple method, a sound made by breath blowing which is input to the microphone. For example, it is possible to distinguish between a voice and breath blowing, and to perform a predetermined process in response to a breath-blowing input.
(9)
The determination unit may determine whether or not the sound input to the microphone is a sound made by a voice.
With configuration (9) above, it is possible to detect, by a simple method, a sound made by a voice input to the microphone. For example, it is possible to distinguish between a voice and breath blowing, and to perform a predetermined process in response to a voice input.
(10)
A plurality of partial segments included in the determination segment may be set to a generally equal length.
With configuration (10) above, it is possible to precisely calculate the amount of components below a predetermined frequency which is determined based on the length of each partial segment of the sound of the determination segment, thereby enabling precise determination.
(11)
The partial segment may be set to a length of 1/700 [sec] or more.
With configuration (11) above, it is possible to detect, by a simple method, a sound made by breath blowing which is input to the microphone.
(12)
The partial segment may be set to a length of 1/400 [sec] or more.
With configuration (12) above, it is possible to detect, by a simple method, a sound made by breath blowing which is input to the microphone.
Note that the present specification discloses an information processing device and an information processing system having units equivalent to those realized by executing the information processing program of (1) to (12) above. The present specification also discloses a sound determination method to be carried out in (1) to (12) above.
Thus, with the storage medium storing an information processing program, the information processing device, the information processing system and the sound determination method set forth above, it is possible to determine an input sound by a simple method.
These and other objects, features, aspects and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.